One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,6)(4,5)(7,8)(12,20)(15,21)(19,24)(22,23)(25,26)(27,32)(28,34)(29,35)(30,45)(31,36)(33,41)(37,47)(38,48)(39,50)(40,54)(42,52)(43,49)(44,53)(46,56)(51,55) involution — undirected(2,5)(3,7)(9,10,13,16)(11,17,18,14)(12,21,20,15)(19,22,24,23)(25,27,31,39)(26,32,36,50)(28,40,42,37)(29,43,30,38)(33,51,53,46)(34,54,52,47)(35,49,45,48)(41,55,44,56)(9,11)(10,14)(12,19)(13,18)(15,22)(16,17)(20,24)(21,23)(25,28,31,42)(26,33,36,53)(27,37,39,40)(29,41,30,44)(32,46,50,51)(34,35,52,45)(38,55,43,56)(47,49,54,48)(1,3,4,7)(2,6,5,8)(11,18)(14,17)(19,24)(22,23)(25,28)(26,34)(27,37)(29,44)(30,41)(31,42)(32,47)(33,45)(35,53)(36,52)(38,56)(39,40)(43,55)(46,48)(49,51)(50,54)(9,12,13,20)(10,15,16,21)(11,19,18,24)(14,22,17,23)(25,29,31,30)(26,35,36,45)(27,38,39,43)(28,41,42,44)(32,48,50,49)(33,52,53,34)(37,55,40,56)(46,47,51,54)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.